Anal intraepithelial neoplasia

The article deals with anal intraepithelial neoplasia, abbreviated AIN.

AIN is now usually classified as either low grade or high grade, as in the uterine cervix.^[1] AIN is considered to be the precursor of anal squamous cell carcinoma.

Anal intraepithelial lesions and anal intraepithelial lesion redirect here.

General

Precursor lesion of anal squamous cell carcinoma.
Usually HPV associated.
- May be prevented by HPV vaccine.
- Strong association with HIV infection.^[1]

Microscopic

DDx:

Grading

AIN is graded much like cervical intraepithelial neoplasia:^[2]^[3]

High-grade anal intraepithelial neoplasia (HGAIN).
Low-grade anal intraepithelial neoplasia (LGAIN).

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Anus (Submitted as "Anal Intraepithelial Neoplasia"), Biopsy:
- HIGH GRADE SQUAMOUS INTRAEPITHIAL LESION (HSIL) of the anus.
- Benign colorectal type mucosa.

Comment:
The HSIL is in keeping with AIN 3.

Block letters

ANAL CANAL, RIGHT UPPER QUADRANT, BIOPSY:
- LOW-GRADE SQUAMOUS INTRAEPITHELIAL LESION (CONDYLOMA ACUMINATUM-LIKE).

ANAL CANAL, LEFT UPPER QUADRANT, BIOPSY:
- LOW-GRADE SQUAMOUS INTRAEPITHELIAL LESION.
- RECTAL MUCOSA WITHIN NORMAL LIMITS.

SKIN LESION, PERIANAL, BIOPSY: 
- ANAL INTRAEPITHELIAL NEOPLASIA 3 (SEVERE DYSPLASIA), WARTY-TYPE.
- MARGIN POSITIVE FOR ANAL INTRAEPITHELIAL NEOPLASIA 3.

Micro

There is dysplastic squamous epithelium with coarse chromatin, nuclear hyperchromasia, nuclear enlargement, irregular nuclear membranes, and an increase nuclear-to-cytoplasmic ratio. Mitotic activity is abundant. Several atypical mitoses are identified.

The dysplastic squamous epithelium shows minimal maturation toward the surface (AIN 3). A sizable portion of the lesion show some maturation to the surface (AIN 2).

Inflammation at the dermal-epidermal interface is minimal and the dermal-epidermal interface is well-demarcated. Focal ulceration is present.

The margin of the biopsy has severely dysplastic epithelium (AIN 3).

References

↑ ^1.0 ^1.1 Dietrich, A.; Hermans, C.; Heppt, MV.; Ruzicka, T.; Schauber, J.; Reinholz, M. (Oct 2015). "Human papillomavirus status, anal cytology and histopathological outcome in HIV-positive patients.". J Eur Acad Dermatol Venereol 29 (10): 2011-8. doi:10.1111/jdv.13205. PMID 26274593.
↑ Roberts, JM.; Jin, F.; Thurloe, JK.; Biro, C.; Poynten, IM.; Tabrizi, SN.; Fairley, CK.; Templeton, DJ. et al. (Jun 2015). "High reproducibility of histological diagnosis of human papillomavirus-related intraepithelial lesions of the anal canal.". Pathology 47 (4): 308-13. doi:10.1097/PAT.0000000000000246. PMID 25938361.
↑ Burgos, J.; Curran, A.; Landolfi, S.; Navarro, J.; Tallada, N.; Guelar, A.; Crespo, M.; Ocaña, I. et al. (Dec 2015). "The effectiveness of electrocautery ablation for the treatment of high-grade anal intraepithelial neoplasia in HIV-infected men who have sex with men.". HIV Med. doi:10.1111/hiv.12352. PMID 26688291.

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[pmid26274593-1] 1.0 ^1.1 Dietrich, A.; Hermans, C.; Heppt, MV.; Ruzicka, T.; Schauber, J.; Reinholz, M. (Oct 2015). "Human papillomavirus status, anal cytology and histopathological outcome in HIV-positive patients.". J Eur Acad Dermatol Venereol 29 (10): 2011-8. doi:10.1111/jdv.13205. PMID 26274593.

[pmid25938361-2] Roberts, JM.; Jin, F.; Thurloe, JK.; Biro, C.; Poynten, IM.; Tabrizi, SN.; Fairley, CK.; Templeton, DJ. et al. (Jun 2015). "High reproducibility of histological diagnosis of human papillomavirus-related intraepithelial lesions of the anal canal.". Pathology 47 (4): 308-13. doi:10.1097/PAT.0000000000000246. PMID 25938361.

[pmid26688291-3] Burgos, J.; Curran, A.; Landolfi, S.; Navarro, J.; Tallada, N.; Guelar, A.; Crespo, M.; Ocaña, I. et al. (Dec 2015). "The effectiveness of electrocautery ablation for the treatment of high-grade anal intraepithelial neoplasia in HIV-infected men who have sex with men.". HIV Med. doi:10.1111/hiv.12352. PMID 26688291.

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Anal intraepithelial neoplasia

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